1. Field of the Invention
The present invention relates to the effective flushing of heating, ventilating and air conditioning systems and more particularly to cleaning of such systems which utilize hydrofluorocarbon and hydrochlorofluorocarbon or Freon refrigerants by the use of solvents selected from the terpene alcohol and terpene hydrocarbon group as a cleaning aid.
2. Background Art
Because of the damage that Freon (CFC) refrigerants were doing to the ozone layer, it has become necessary for the development of alternative refrigerants which are more environmentally friendly. Dupont and International Chemicals are two such companies who developed hydrofluorocarbon and hydrochlorofluorocarbon refrigerants, both of which are much safer to the environment and have an ozone depletion factor of one rather than an ozone depletion factor of 8.0, as is found for Freon refrigerants.
With the advent of such new refrigerants came new problems associated with their use. One particular problem is that of cleaning of heating, ventilating and air conditioning systems employing these new refrigerants. When existing systems changed over to the new hydrofluorocarbon and hydrochlorofluorocarbon refrigerants from the Freon type refrigerants, it was crucial and absolutely essential that all of the Freon refrigerant by complete completely removed before recharging the system with the new refrigerant. Any trace of the old refrigerant which is left beyond will cause catastrophic failure of the compressor system. Thus, it becomes extremely necessary to have proper flushing out of these materials. Previously, Freon liquids were used to clean heating, ventilating and air conditioning systems but were later determined to have unacceptable side effects in that such cleaners evaporate quickly but are very destructive to the ozone layer.
Subsequently, Allied Chemical Company developed a flushing solvent called "Genesolve" which is an hydrochlorofluorocarbon liquid that was intended as an ozone safe compressor system flushant. The hydrochlorofluorocarbon liquid is much safer to the ozone layer but has some serious drawbacks that render it unacceptable for use as a compressor system flushant. These objections include the extremely powerful solvent ability of the hydrochlorofluorocarbon liquid. As such, it will attack the gasket materials in any devices used to inject the flushant into the compressor system. It also acts as to attack the gasket materials utilized in the refrigerant compressor itself. The hydrochlorofluorocarbon liquid attacks even the most chemically resistant gasket materials such as fluoroelastomers, neoprene and butadiene.
Other solvents, which were experimented with for use as a flushant, such as isoppropyl/acetone mixtures are extremely flammable and non-biodegradable, thus making them unacceptable for use as a cleaning aid. Petroleum distillates on the other hand, such as mineral spirits, do not evaporate quickly enough and are generally very flammable and therefore also dangerous to use.